Use of Metformin in Combination with a Glucokinase Activator and Compositions Comprising Metformin and a Glucokinase Activator

ABSTRACT

The present invention provides uses of a glucokinase activator in combination with metformin. Uses include treating type 2 diabetes, lowering blood glucose, improving insulin sensitivity, enhancing phosphorylation of glucose, and improving the therapeutic effectiveness of metformin. The invention also provides pharmaceutical compositions that comprise a GK activator and metformin. The invention also provides a salt formed between metformin and a GK activator.

BACKGROUND OF THE INVENTION

Diabetes is characterized by impaired glucose metabolism, and manifestsitself, among other ways, by elevated blood glucose (BG) levels inuntreated diabetic patients. Diabetes is generally known as being one oftwo types: type 1 diabetes (or insulin-dependent diabetes mellitus),which arises when patients lack insulin-producing (β cells in theirpancreatic glands; and type 2 diabetes (or non-insulin dependentdiabetes mellitus), which arises when patients have impaired β-cellfunction, in addition to a range of other abnormalities.

Treatment of type 2 diabetes can include the administration of commonagents that stimulate (β-cell function or that enhance the tissuesensitivity of patients towards insulin. Various agents are known tostimulate β-cell function, including, for example, sulfonylureas, suchas tolbutamide, glibenclamide, glipizide, chlorpropamide, andgliclazide, and repaglinide. Other agents are known to enhance tissuesensitivity towards insulin, such as metformin.

Although such common agents are widely used in the treatment of type 2diabetes, the therapy is often leads to unsatisfactory results. In manypatients, such treatments do not normalize BG levels to the desireddegree, which places patients at a higher risk of acquiring furtherdiabetic complications. Furthermore, these treatments are known to causeadverse effects in many patients. For example, the sulfonylureas mayinduce hypoglycemia when taken alone or in combination with other drugs.And while metformin does not induce hypoglycemia to the same degree assulfonylureas, it has other adverse effects. For example, metformin maycause gastrointestinal distress, where the incidence of such distressmay increase with higher doses. Long-term use of metformin can alsocause increased homocysteine levels and can lead to malabsorption ofvitamin B12. Metformin may also induce production of lactate, which cancontribute to lactic acidosis in some patient populations.

In recent years, metformin has been approved for use in combination withother antidiabetic drugs. For example, metformin has been combined withcertain sulfonylureas, including glipizide and glibenclamide. Metforminhas also been combined with agents that stimulate PPAR-γ receptors, suchas pioglitazone and rosiglitazone, and with agents that stimulate therelease of insulin from the pancreas, such as repaglinide.

But in any combination therapy, metformin can still exhibit adverseeffects, including those described above. Therefore, there is a need todiscover agents that, when used with metformin, may exhibit asynergistic effect on glycemic control, thereby allowing a subjects toreduce their daily intake of metformin.

Glucokinase (GK) is an enzyme that, among other things, facilitatesphosphorylation of glucose to glucose-6-phosphate. In vertebrates,GK-mediated glucose phosphorylation typically occurs in cells in theliver, pancreas, gut, and brain. In each of these organs, GK can play arole in regulating carbohydrate metabolism by acting as a glucosesensor, triggering shifts in metabolism or cell function in response torising and/or falling levels of BG.

Small-molecule GK activators are useful in treating type 2 diabetesbecause they can activate GK, and thereby indirectly reduce the body'sdemand for insulin. WO 2005/066145 describes novel compounds that areuseful as GK activators, and are therefore useful, among other things,for the treatment of type 2 diabetes. Among the disclosed compounds are{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid and pharmaceutically acceptable salts thereof (referred tocollectively as “Urea Derivatives 1” or “UD1”). The free acid,{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfany}-aceticacid, is referred to herein as “UD1-FA”.

FIELD OF THE INVENTION

The invention provides for the use of a glucokinase (GK) activator incombination with an antidiabetic drug, such as metformin, for thetreatment of type 2 diabetes and other conditions. The invention alsoprovides pharmaceutical compositions comprising a GK activator and anantidiabetic drug, such as metformin.

BRIEF SUMMARY OF THE INVENTION

The invention provides for the use of a glucokinase (GK) activator incombination with metformin for the treatment of type 2 diabetes andrelated disorders.

In one aspect, the invention provides methods of treating type 2diabetes by administering to a subject a GK activator in combinationwith metformin. In some embodiments, the GK activator and metformin areadministered simultaneously, either in separate dosage forms or the samedosage form. But in other embodiments, the GK activator and metforminare not necessarily administered simultaneously, but are insteadadministered according to a sequence. In other embodiments, either theGK activator or metformin is administered subsequent to the other, sothat an amount of both are simultaneously present in the subject (asdetermined, for example, by analysis of the subject's blood or bloodplasma).

In another aspect, the invention provides methods of treating type 1diabetes by administering to a subject a GK activator in combinationwith metformin. In some embodiments, the GK activator and metformin areadministered simultaneously, either in separate dosage forms or the samedosage form. But in other embodiments, the GK activator and metforminare not necessarily administered simultaneously, but are insteadadministered according to a sequence. In other embodiments, either theGK activator or metformin is administered subsequent to the other, sothat an amount of both are simultaneously present in the subject (asdetermined, for example, by analysis of the subject's blood or bloodplasma).

In another aspect, the invention provides methods of loweringblood-glucose in a subject by administering to the subject a GKactivator in combination with metformin. In some embodiments, the GKactivator and metformin are administered simultaneously, either inseparate dosage forms or the same dosage form. But in other embodiments,the GK activator and metformin are not necessarily administeredsimultaneously, but are instead administered according to a sequence. Inother embodiments, either the GK activator or metformin is administeredsubsequent to the other, so that an amount of both are simultaneouslypresent in the subject (as determined, for example, by analysis of thesubject's blood or blood plasma).

In another aspect, the invention provides methods of enhancingphosphorylation of glucose in a subject by administering to the subjecta GK activator in combination with metformin. In some embodiments, theGK activator and metformin are administered simultaneously, either inseparate dosage forms or the same dosage form. But in other embodiments,the GK activator and metformin are not necessarily administeredsimultaneously, but are instead administered according to a sequence. Inother embodiments, either the GK activator or metformin is administeredsubsequent to the other, so that an amount of both are simultaneouslypresent in the subject (as determined, for example, by analysis of thesubject's blood or blood plasma).

In another aspect, the invention provides methods of improving insulinsensitivity in a subject by administering to the subject a GK activatorin combination with metformin. In some embodiments, the GK activator andmetformin are administered simultaneously, either in separate dosageforms or the same dosage form. But in other embodiments, the GKactivator and metformin are not necessarily administered simultaneously,but are instead administered according to a sequence. In otherembodiments, either the GK activator or metformin is administeredsubsequent to the other, so that an amount of both are simultaneouslypresent in the subject (as determined, for example, by analysis of thesubject's blood or blood plasma).

In another aspect, the invention provides pharmaceutical compositionscomprising a GK activator and metformin. In some embodiments, thepharmaceutical composition also comprises a pharmaceutically acceptablecarrier, excipient, diluent, or a mixture thereof.

In another aspect, the invention provides a metformin salt of a GKactivator, and to pharmaceutical compositions comprising said salt. In afurther aspect, the provides any of the aforementioned methods, suchthat the method comprises administering a metformin salt of a GKactivator to a subject.

Additional features and aspects of the present invention are describedhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a PXRD diffractogram for sample containing a crystalline1:1 metformin salt of UD1-FA.

DETAILED DESCRIPTION OF THE INVENTION I. General

In the early stages, patients with type 2 diabetes may exhibit adecreasing ability of their pancreas to secrete sufficient insulin tocontrol post-prandial blood-glucose levels. At first, type 2 diabeticsmay be able to control progression of the disease by following dietaryrestrictions, such as consuming foods having a low glycemic index. Butas the disease progresses, diet alone is insufficient to controlblood-glucose levels. Thus, medical intervention becomes necessary. Atthis stage (or even in advance of this stage), physicians may prescribean oral antidiabetic agent to aid in glycemic control. Common oralantidiabetic agents include, for example, sulfonylureas, such asglibenclamide, and biguanides, such as metformin.

These common antidiabetics may have undesirable side-effects in certainpatient populations, and may also fail to provide desirable levels ofglycemic control. Thus, scientists have continued to search forcompounds that can replace or supplement the use of these commonantidiabetics. Glucokinase (GK) activators represent one such class ofcompounds.

GK is an enzyme that, among other things, facilitates phosphorylation ofglucose to glucose-6-phosphate. In vertebrates, GK-mediatedphosphorylation generally occurs in cells in the liver, pancreas, gut,and brain. In each of these organs, GK can play a role in regulatingcarbohydrate metabolism by acting as a glucose sensor, triggering shiftsin metabolism or cell function in response to rising and/or fallinglevels of blood-glucose.

Small-molecule GK activators are useful in treating type 2 diabetesbecause they can enhance the rate of glucose phosphorylation, andthereby reduce the amount of glucose in the blood. Therefore, GKactivators lower the body's demand for insulin, especially followingintake of food. In this way, GK activators provide an alternatetreatment option for type 2 diabetics who otherwise may have difficultyachieving effective glycemic control.

Various GK activators are known. For example,{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid is a GK activator. The preparation and pharmaceutical use of thiscompound and salts thereof are described in WO 2005/066145.

As described in further detail below, it was discovered that GKactivators may exhibit a synergistic effect in lowering blood glucoselevels when administered in combination with metformin. Type 2 diabeticsoften take metformin in large amounts, such as 1000-2500 mg of metformindaily. See Remington's, 21st edition, pp. 1454-55 (2006). It is notexpected that metformin will have much of an effect on lowering glucosewhen administered at smaller doses. Id. at 1455 (noting that certaintherapeutic benefits are not generally observed until a subject isadministered at least 1000 mg daily of metformin). Because a GKactivator and metformin may have a synergistic effect, one canadminister to a subject a smaller amount of metformin (e.g., asuboptimal amount) and achieve therapeutic benefits, such asblood-glucose lowering, that would otherwise only have been observedwhen higher doses (including prohibitively higher doses) of metforminare administered.

Thus, in at least one aspect, the invention provides for the use of aglucokinase (GK) activator in combination with metformin, for thetreatment of type 2 diabetes, type 1 diabetes, and other relatedconditions. Such related conditions include, but are not limited to:metabolic syndrome, glucose intolerance, hyperglycemia, dyslipidemia,hypertriglyceridemia, syndrome X, insulin resistance, impaired glucosetolerance (IGT), obesity, diabetic dyslipidemia, hyperlipidemia,arteriosclerosis, atherosclerosis, other cardiovascular diseases,hypertension, metabolic disorders where activation of GK is beneficial,and complications resulting from or associated with diabetes, including,but not limited to, neuropathy, retinopathy, nephropathy, and impairedwound healing.

The invention also relates to pharmaceutical compositions comprising aGK activator and metformin.

II. Pharmaceutical Compositions

In some embodiments of the invention, metformin and/or a GK activatormay be included within a pharmaceutical composition. In some suchembodiments, a single pharmaceutical composition comprises bothmetformin and a GK activator. In some further such embodiments, two ormore pharmaceutical compositions are provided, where at least onepharmaceutical composition comprises metformin and at least one otherpharmaceutical composition comprises a GK activator. As used herein, theterm “pharmaceutical composition” refers to a solid composition (e.g., agranulated powder) that contains a pharmaceutically active ingredient(e.g., metformin and/or a GK activator) and at least a carrier, diluent,or excipient, where none of the ingredients is generally biologicallyundesirable at the administered quantities. In some embodiments,metformin and the GK activator are included in separate pharmaceuticalcompositions, each of which also includes a pharmaceutically acceptablecarrier, diluent, excipient, or mixture thereof. In other embodiments,metformin and the GK activator are included in the same pharmaceuticalcomposition, which also includes a pharmaceutically acceptable carrier,diluent, excipient, or mixture thereof

As used herein, the term “a mixture of” or “a mixture thereof” refers toany mixture of two or more materials and/or compositions that would beencompassed within the list that follows or precedes the phrase,respectively. The phrase does not refer to any particular type ofmixture. Thus, the “mixture” is not necessarily an intimate mixture, ahomogeneous mixture, etc. Furthermore, the “mixture” need not contain arepresentative of each element in the list. For example, if acomposition comprises “A, B, C, or a mixture thereof” the termcontemplates mixtures of A and B (with no C present), mixtures of B andC (with no A present), mixtures of A and C (with no B present), as wellas mixtures of A, B, and C. As a further illustration, suppose that A,B, or C define generic categories (e.g., a polysorbate), where, forexample, A¹ and A² are species or subgenuses encompassed by the genus A.In that instance, if a composition comprises “A, B, C, or a mixturethereof,” the term also contemplates mixtures of A1 and A² (where no Band no C are present in the mixture).

Metformin

N,N-dimethylimidodicarbonimidic diamide is often referred to asmetformin or 1,1-dimethylbiguanide. Metformin can exist as a free base,or may form salts, including pharmaceutically acceptable salts, such asa hydrochloride salt (e.g., a mono-hydrochloride salt). See Remington's,21st edition, pp. 1454-55 (2006). As used herein, the term “metformin”is not limited to the free base, but also includes metformin salts, suchas pharmaceutically acceptable salts of metformin, hydrochloride saltsof metformin, and a mono-hydrochloride salt. As used herein, the term“1,1-dimethylbiguanide” refers only to the free base unless the textexpressly indicates that salted forms are also contemplated.

The metformin may be included in any suitable dosage form. For example,metformin may exist in a powder, a tablet, a capsule, and the like. Suchdosage forms may, in some embodiments, also include specializedcoatings, matrices, and the like to give effect a sustained release, acontrolled release, enteric release, etc. In some embodiments, metforminmay exist in a dosage form with another therapeutically activeingredient. In some such embodiments, the therapeutically activeingredient is a GK activator. In some embodiments, the therapeuticallyactive ingredient is a liver-selective GK activator. In someembodiments, the therapeutically active ingredient is UD1.

As used throughout this specification, the term “pharmaceuticallyacceptable salt,” refers to salts of a free acid or a free base whichare not biologically undesirable and are generally prepared by reactingthe free base with a suitable organic or inorganic acid or by reactingthe acid with a suitable organic or inorganic base. The term may be usedin reference to any compound, including 1,1-dimethylbiguanide, and a GKactivator (having a free acid or free base functionality), etc.Representative salts include the following salts: Acetate,Benzenesulfonate, Benzoate, Bicarbonate, Bisulfate, Bitartrate, Borate,Bromide, Calcium Edetate, Camsylate, Carbonate, Chloride, Clavulanate,Citrate, Dihydrochloride, Edetate, Edisylate, Estolate, Esylate,Fumarate, Gluceptate, Gluconate, Glutamate, Glycollylarsanilate,Hexylresorcinate, Hydrabamine, Hydrobromide, Hydrochloride,Hydroxynaphthoate, Iodide, Isethionate, Lactate, Lactobionate, Laurate,Malate, Maleate, Mandelate, Mesylate, Methylbromide, Methylnitrate,Methylsulfate, Monopotassium Maleate, Mucate, Napsylate, Nitrate,N-methylglucamine, Oxalate, Pamoate (Embonate), Palmitate, Pantothenate,Phosphate/diphosphate, Polygalacturonate, Potassium, Salicylate, Sodium,Stearate, Subacetate, Succinate, Tannate, Tartrate, Teoclate, Tosylate,Triethiodide, Trimethylammonium and Valerate. When an acidic substituentis present (e.g., in a GK activator), such as —COOH, there can be formedthe ammonium, morpholinium, sodium, potassium, barium, calcium salt, andthe like, for use as the dosage form. When a basic group is present(e.g., in a GK activator or 1,1-dimethylbiguanide), such as amino or abasic heteroaryl radical, such as pyridyl, an acidic salt, such ashydrochloride, hydrobromide, phosphate, sulfate, trifluoroacetate,trichloroacetate, acetate, oxalate, maleate, pyruvate, malonate,succinate, citrate, tartarate, fumarate, mandelate, benzoate, cinnamate,methanesulfonate, ethanesulfonate, picrate and the like, and includeacids related to the pharmaceutically-acceptable salts listed in StephenM. Berge, et al., Journal of Pharmaceutical Science, Vol. 66 (1), pp.1-19 (1977).

GK Activators

As used herein, a “GK activator” is a compound that activates GKactivity in a mammalian subject, such as a human, in direct or indirectresponse to the presence of the compound, or a metabolite thereof, inthe subject. WO 2005/066145 provides a non-limiting list of compoundsthat are GK activators. In some embodiments, the GK activator is a smallmolecule, such as a molecule having a molecular weight between 200 amuand 2000 amu, or between 200 amu and 1200 amu, or between 200 amu and800 amu. Further, GK activators may activate GK wherever GK is present,but some may be selective to certain GK activity in certain systems ororgans. For the treatment of type 2 diabetes and related disorders, oneis generally concerned with GK activation in the pancreas and/or theliver. In some embodiments, the GK activator is a liver selective GKactivator, meaning that the GK activator directly or indirectlyincreases glucose utilization in the liver at doses that do not induce asubstantial increase in insulin secretion by the pancreas in response toglucose (e.g., less than a 25% increase, or less than a 15% increase, orless than a 10% increase, or less than a 5% increase, or less than a 3%increase in insulin secretion by the pancreas in response to glucose).In some embodiments, the GK activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof.

Combination Therapy

In some embodiments of the invention, metformin is administered incombination with a GK activator, or in combination with aliver-selective GK activator, or in combination with UD1. Administrationis typically to a subject, such as a human, for the treatment of adisease, disorder, or condition.

As used herein, “administer” or “administering” means to introduce, suchas to introduce to a subject a compound or composition. The term is notlimited to any specific mode of delivery, and can include, for example,subcutaneous delivery, intravenous delivery, intramuscular delivery,intracisternal delivery, delivery by infusion techniques, transdermaldelivery, oral delivery, nasal delivery, and rectal delivery.Furthermore, depending on the mode of delivery, the administering can becarried out by various individuals, including, for example, ahealth-care professional (e.g., physician, nurse, etc.), a pharmacist,or the subject (i.e., self-administration).

As used herein, “treat” or “treating” or “treatment” can refer to one ormore of: delaying the progress of a disease, disorder, or condition;controlling a disease, disorder, or condition; delaying the onset of adisease, disorder, or condition; ameliorating one or more symptomscharacteristic of a disease, disorder, or condition; or delaying therecurrence of a disease, disorder, or condition, or characteristicsymptoms thereof, depending on the nature of the disease, disorder, orcondition and its characteristic symptoms.

As used herein, “subject” refers to any mammal such as, but not limitedto, humans, horses, cows, sheep, pigs, mice, rats, dogs, cats, andprimates such as chimpanzees, gorillas, and rhesus monkeys. In anembodiment, the “subject” is a human. In another embodiment, the“subject” is a human who exhibits one or more symptoms characteristic ofa disease, disorder, or condition. In another embodiment, the “subject”is a human who has a disease, disorder, or condition in which GK isinvolved. The term “subject” does not require one to have any particularstatus with respect to a hospital, clinic, or research facility (e.g.,as an admitted patient, a study participant, or the like).

As used herein, the term “in combination with,” when used, for example,in the context of administering a compound in combination with anothercompound, places no limit on the method, mode, form, etc. of theadministration, so long as the administration results in both compoundsbeing simultaneously biologically available to a subject (e.g., presentin the blood plasma) at a common point in time.

As noted above, in some embodiments, metformin is administered incombination with a GK activator, or in combination with aliver-selective GK activator, or in combination with UD1. In some suchembodiments, metformin and a GK activator are administeredsimultaneously, for example, via oral administration. For example,metformin and a GK activator are delivered in a common dosage form,where the dosage form comprises both metformin and a GK activator, or aliver-selective GK activator, or UD1. In another example, metformin anda GK activator are delivered in two or more dosage forms that areadministered at approximately the same time (e.g., within less than 30minutes, or within less than 15 minutes, or within less than 10 minutes,or within less than5 minutes, or within less than 2 minutes of eachother), where at least one dosage form comprises metformin and anotherdosage form comprises a GK activator, or a liver-selective GK activator,or UD1. In further such embodiments, metformin and a GK activator areadministered sequentially, preferably via oral administration. Forexample, metformin or the GK activator can be administered about 30minutes apart, or about 1 hour apart, or about 2 hours apart, or about 4hours apart, or about 8 hours apart, or about 12 hours apart, where onemetformin is administered earlier than the GK activator, or vice versa.In even further such embodiments, either metformin or the GK activatoris administered subsequent to the other, so long as the administrationresults in both compounds being simultaneously biologically available toa subject (e.g., present in the blood plasma) at a common point in time.For example, one can be administered about 30 minutes after, or about 1hour after, or about 2 hours after, or about 4 hours after, or about 8hours after, or about 12 hours after the administration of the other.

Dosage Forms

The pharmaceutical compositions, described herein, can be packaged in aform for oral administration as discrete units (i.e., dosage forms),such as capsules, tablets, sachets, and the like. Preparation of thesolid compositions in forms intended for oral administration is withinthe ability of one skilled in the art, including the selection ofpharmaceutically acceptable additional ingredients from the groupslisted above in order to provide pharmaceutically elegant and palatablepreparations. Such pharmaceutical compositions may be prepared bymethods known in the pharmaceutical formulation art, for example, seeRemington's Pharmaceutical Sciences, 18th Ed., (Mack Publishing Company,Easton, Pa., 1990).

In some embodiments, administration of metformin in combination with aGK activator can include administration of a dosage form that comprisesmetformin and a GK activator, or a liver-selective GK activator, or UD1.In some further embodiments, administration of metformin in combinationwith a GK activator can include administration of two or more dosageforms, where at least one dosage form comprises metformin and anotherdosage form comprises a GK activator, or a liver-selective GK activator,or UD1.

Dosage Quantities

In embodiments of the invention, an amount of a GK activator, or aliver-selective GK activator, or UD1, is administered to a subject(e.g., a human) in combination with metformin. The amount of the GKactivator administered can vary depending on various factors, includingbut not limited to, the weight of the subject, the nature and/or extentof the subject's disease, etc. In some embodiments, a GK activator, or aliver-selective GK activator, or UD1, is administered to a subject(e.g., a human), in combination with metformin, in an amount that rangesfrom 10 mg/day to 1000 mg/day, or from 25 mg/day to 800 mg/day, or from37 mg/day to 750 mg/day, or from 75 mg/day to 700 mg/day, or from 100mg/day to 600 mg/day, or from 150 mg/day to 500 mg/day, or from 200mg/day to 400 mg/day. In some further embodiments, a GK activator, or aliver-selective GK activator, or UD1, is administered to a subject(e.g., a human), in combination with metformin, in an amount of about100 mg/day, or about 200 mg/day, or about 300 mg/day, or about 400mg/day, or about 500 mg/day. In even some further embodiments, a GKactivator, or a liver-selective GK activator, or UD1, is administered toa subject (e.g., a human), in combination with metformin, in atherapeutically effective amount. As used herein, the term“therapeutically effective amount” refers to an amount of an activeingredient (e.g., GK activator, or a liver-selective GK activator, orUD1) that elicits the biological or medicinal response in a tissue,system, or subject that is being sought by a researcher, veterinarian,medical doctor, patient or other clinician, which includes reduction oralleviation of the symptoms of the disease being treated.

As a monotherapy, metformin may be administered to human subjects inamounts between 1000 mg/day and 2500 mg/day. See Remington's, 21stedition, pp. 1454-55 (2006). In smaller doses, metformin may offernegligible therapeutic benefits when administered as a monotherapy. Id.at 1455. In embodiments of the invention, a GK activator, or aliver-selective GK activator, or UD1, is administered to a subject(e.g., a human) in combination with an amount of metformin. In someembodiments, the amount of metformin administered to a subject (e.g., ahuman) ranges from 250 mg/day to 2500 mg/day, or from 500 mg/day to 1500mg/day, or from 250 mg/day to 1000 mg/day, or from 350 mg/day to 850mg/day, or from 400 mg/day to 750 mg/day. In some further embodiments,the amount of metformin administered to a subject (e.g., a human) isabout 250 mg/day, or about 350 mg/day, or about 500 mg/day, or about 600mg/day, or about 700 mg/day, or about 750 mg/day, or about 850 mg/day,or about 1000 mg/day, or about 1200 mg/day, or about 1500 mg/day, orabout 2000 mg/day, or about 2500 mg/day. In some further embodiments,the amount of metformin administered to a subject (e.g., a human) is atherapeutically effective amount.

In some embodiments of the invention, a GK activator, or aliver-selective GK activator, or UD1, is administered to a subject(e.g., a human) in combination with a suboptimal amount of metformin. Asused herein in reference to metformin, a “suboptimal amount” is anamount that is less than a therapeutically effective amount as amonotherapy in a typical subject (e.g., a human subject, or a humansubject who suffers from type 2 diabetes or type 1 diabetes, or a humansubject in need of glycemic control). In some such embodiments, thesuboptimal amount of metformin is an amount that ranges from 0.01 mg/dayto 1000 mg/day, or from 10 mg/day to about 850 mg/day, or from 37 mg/dayto 750 mg/day, or from 50 mg/day to 700 mg/day, or from 75 mg/day to 600mg/day, or from 100 mg/day to 500 mg/day.

III. Methods of Treatment

In another aspect, the invention provides methods of treating type 2diabetes by administering to a subject a GK activator, or aliver-selective GK activator, or UD1, in combination with metformin,according to any of the embodiments described in the foregoing sections.

In some embodiments, the invention provides methods of treating type 2diabetes by administering to a subject a glucokinase activator incombination with a suboptimal amount of metformin. In some embodiments,the glucokinase activator is a liver-selective glucokinase activator. Insome embodiments, the glucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. In some embodiments,the glucokinase activator and the suboptimal amount of metformin areadministered to the subject simultaneously. In some embodiments, theglucokinase activator and the suboptimal amount of metformin areadministered, such that one is administered subsequent to the other.

In another aspect, the invention provides methods of treating type 1diabetes by administering to a subject a GK activator, or aliver-selective GK activator, or UD1, in combination with metformin,according to any of the embodiments described in the foregoing sections.

In another aspect, the invention provides methods of loweringblood-glucose in a subject by administering to the subject a GKactivator, or a liver-selective GK activator, or UD1, in combinationwith metformin, according to any of the embodiments described in theforegoing sections.

In some embodiments, the invention provides methods of lowering bloodglucose in a subject by administering to the subject a glucokinaseactivator in combination with a suboptimal amount of metformin. In someembodiments, the glucokinase activator is a liver-selective glucokinaseactivator. In some embodiments, the glucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. In some embodiments,the glucokinase activator and the suboptimal amount of metformin areadministered to the subject simultaneously. In some embodiments, theglucokinase activator and the suboptimal amount of metformin areadministered, such that one is administered subsequent to the other.

In another aspect, the invention provides methods of enhancingphosphorylation of glucose in a subject by administering to the subjecta GK activator, or a liver-selective GK activator, or UD1, incombination with metformin, according to any of the embodimentsdescribed in the foregoing sections.

In some embodiments, the invention provides methods of enhancingphosphorylation of glucose in a subject by administering to the subjecta glucokinase activator in combination with a suboptimal amount ofmetformin. In some embodiments, the glucokinase activator is aliver-selective glucokinase activator. In some embodiments, theglucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido] -thiazol-5-ylsulfanyl}-acetic acid or a pharmaceutically acceptable salt thereof.In some embodiments, the glucokinase activator and the suboptimal amountof metformin are administered to the subject simultaneously. In someembodiments, the glucokinase activator and the suboptimal amount ofmetformin are administered, such that one is administered subsequent tothe other.

In another aspect, the invention provides methods of improving insulinsensitivity in a subject by administering to the subject a GK activator,or a liver-selective GK activator, or UD1, in combination withmetformin, according to any of the embodiments described in theforegoing sections.

In some embodiments, the invention provides methods of improving insulinsensitivity in a subject by administering to the subject a glucokinaseactivator in combination with a suboptimal amount of metformin. In someembodiments, the glucokinase activator is a liver-selective glucokinaseactivator. In some embodiments, the glucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. In some embodiments,the glucokinase activator and the suboptimal amount of metformin areadministered to the subject simultaneously. In some embodiments, theglucokinase activator and the suboptimal amount of metformin areadministered, such that one is administered subsequent to the other.

In another aspect, the invention provides methods of boosting orenhancing the therapeutic effectiveness (in terms of enhancedglucose-lowering effect) of metformin by administering to a subject a GKactivator, or a liver-selective GK activator, or UD1, in combinationwith metformin, according to any of the embodiments described in theforegoing sections.

In some embodiments, the invention provides methods of enhancing thetherapeutic effectiveness of metformin by administering to the subject aglucokinase activator in combination with metformin. In someembodiments, the glucokinase activator is a liver-selective glucokinaseactivator. In some embodiments, the glucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. In some embodiments,the glucokinase activator and the suboptimal amount of metformin areadministered to the subject simultaneously. In some embodiments, theglucokinase activator and the suboptimal amount of metformin areadministered, such that one is administered subsequent to the other. Insome embodiments, the metformin is administered as a suboptimal amountof metformin.

In another aspect, the invention provides methods of treating acondition comprising administering to a subject a GK activator, or aliver-selective GK activator, or UD1, in combination with metformin,according to any of the embodiments described in the foregoing sections,wherein the condition is selected from metabolic syndrome, glucoseintolerance, hyperglycemia, dyslipidemia, hypertriglyceridemia, syndromeX, insulin resistance, impaired glucose tolerance (IGT), obesity,diabetic dyslipidemia, hyperlipidemia, arteriosclerosis,atherosclerosis, other cardiovascular diseases, hypertension, metabolicdisorders where activation of GK is beneficial, or complicationsresulting from or associated with diabetes, including, but not limitedto, neuropathy, retinopathy, nephropathy, and impaired wound healing.

IV. Pharmaceutical Compositions Containing Metformin and a GK Activator

In a further aspect of the invention, a GK activator, or aliver-selective GK activator, or UD1, can be included in apharmaceutical composition with metformin. In some embodiments, the GKactivator and the metformin are intermixed, optionally in the presenceof at least one other pharmaceutically acceptable carrier, diluent, orexcipient, such that the GK activator and metformin are homogeneouslydistributed throughout the composition. In other embodiments, apharmaceutical composition comprises both a GK activator and metformin,and optionally at least one other pharmaceutically acceptable carrier,diluent, or excipient, where the GK activator and the metformin are nothomogeneously distributed throughout the composition.

In some embodiments, the invention provides a pharmaceutical compositionof a glucokinase activator, a suboptimal amount of metformin, and atleast one pharmaceutically acceptable carrier, excipient, diluent, or amixture thereof. In some embodiments, the glucokinase activator is aliver-selective glucokinase activator. In some embodiments, theglucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. In some embodiments,the glucokinase activator and metformin are distributed homogeneouslythroughout the pharmaceutical composition. In some embodiments, theglucokinase activator and metformin are not distributed homogeneouslythroughout the pharmaceutical composition.

As a non-limiting example, the composition may be a solid compositionthat comprises a bi-layered granule, where one layer in the granule isenriched in a GK activator and the other layer in the granule isenriched in metformin. In some embodiments, the pharmaceuticalcomposition includes granules that each include a glucokinase activatorand metformin. Such granules can be made by any suitable granulationmethod known in the art, including but not limited to, various drygranulation and wet granulation techniques. Furthermore, the particlesize and the distribution of particle sizes of the granules can beadjusted according to known techniques to achieve release profiles,dissolution, and the like. In some embodiments, the invention provides apharmaceutical composition that comprises granules that each comprises aGK activator and metformin. In some such embodiments, at least 80%, orat least 85%, or at least 90%, or at least 95% (by weight) of saidgranules have a particle size that is between 1 μm and 1 mm. Further, insome such embodiments, at least 80%, or at least 85%, or at least 90%,or at least 95% (by weight) of said granules have a particle size thatis between 1 μm and 500 μm.

The granules can be homogeneous or heterogeneous. Homogeneous granulescan have an equal distribution of one of or both the glucokinaseactivator and metformin, throughout each granule. Alternatively, thegranules can be heterogeneous, such that some portions of each granulehave a higher concentration of glucokinase activator than otherportions. The higher concentration of the glucokinase activator and/orthe metformin can be achieved in a variety of methods, such as, forexample, via layers. The granules can include one or more layers, whereeach layer can include the glucokinase activator or the metformin, or acombination of the two. For example, one layer can include theglucokinase activator, and another layer the metformin. Alternatively,one layer can include the glucokinase activator in combination with themetformin at one concentration, and a second layer of both theglucokinase activator and metformin at a second concentration.

In some embodiments, at least a portion of the granules have acomposition such that the glucokinase activator and the metformin aredistributed homogeneously throughout each granule with that portion. Insome embodiments, at least a portion of the granules have a compositionsuch that each granule in that portion has at least two layers, whereinone layer is enriched in the glucokinase activator and the other layeris enriched in metformin.

In any embodiment where metformin and/or a GK activator are included ina pharmaceutical composition, such pharmaceutical compositions may be ina form suitable for oral use, for example, as tablets, troches,lozenges, aqueous, or oily suspensions, dispersible powders or granules,emulsions, hard or soft capsules, or syrups or elixirs. Compositionsintended for oral use may be prepared according to any known method, andsuch compositions may contain one or more agents selected from the groupconsisting of sweetening agents, flavoring agents, coloring agents, andpreserving agents in order to provide pharmaceutically elegant andpalatable preparations. Tablets may contain the active ingredient inadmixture with non-toxic pharmaceutically-acceptable excipients whichare suitable for the manufacture of tablets. These excipients may be forexample, inert diluents, such as calcium carbonate, sodium carbonate,lactose, calcium phosphate or sodium phosphate; granulating anddisintegrating agents, for example corn starch or alginic acid; bindingagents, for example, starch, gelatin or acacia; and lubricating agents,for example magnesium stearate, stearic acid or talc. The tablets may beuncoated or they may be coated by known techniques to delaydisintegration and absorption in the gastrointestinal tract and therebyprovide a sustained action over a longer period. For example, a timedelay material such as glyceryl monostearate or glyceryl distearate maybe employed. They may also be coated by the techniques described in U.S.Pat. Nos. 4,356,108; 4,166,452; and 4,265,874, to form osmotictherapeutic tablets for controlled release.

Metformin Salts

In another aspect, the invention provides a salt between a GK activatorand metformin, where the GK activator has at least one acidic group,such as, for example, a —CO₂H group. In some such embodiments, the GKactivator is a liver-selective GK activator, or UD1. In general, thestoichiometric ratio between metformin and the GK activator is 1:1. Theinvention does not require any particular amount of the salt to bepresent; a single pairing between a GK activator ion and a metformincounterion is sufficient. Larger quantities of the salt can be present,however. For example, in some embodiments, at least 5%, or at least 10%,or at least 20%, or at least 40%, or at least 60%, or at least 80%, orat least 90%, or at least 95% of the GK activator (e.g., UD1) is presentin a composition as a salt with metformin (based on the total number ofmoles of said GK activator (e.g., UD1) present in the composition). Insome further embodiments, at least 5%, or at least 10%, or at least 20%,or at least 40%, or at least 60%, or at least 80%, or at least 90%, orat least 95% of the metformin is present in a composition as a salt witha GK activator (e.g., UD1) (based on the total number of moles ofmetformin present in the composition). The salts between a GK activatorand metformin need not have any particular crystalline structure ordegree of crystallinity. The preparation of such salts is described inthe examples below.

In some embodiments, the invention provides a pharmaceutical compositioncomprising a metformin salt of a GK activator, or a liver-selective GKactivator, or UD1, and further comprising a pharmaceutically acceptablecarrier, diluent, or excipient, or mixtures thereof. In some suchembodiments, the pharmaceutical composition may also comprise additionalquantities of metformin and/or a GK activator (e.g., a liver selectiveGK activator or UD1).

In some embodiments, the invention provides a salt of one molecularcation and one molecular anion, where the molecular cation is a cationof 1,1,-dimethylbiguanide and the molecular anion is an anion of aglucokinase activator. In some embodiments, the glucokinase activator isa liver-selective glucokinase activator. In some embodiments, theglucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid. In some embodiments, the invention provides a pharmaceuticalcomposition of the salt described above and at least a pharmaceuticallyacceptable carrier, excipient, diluent, or a mixture thereof.

In any of the aforementioned methods of treatment, administration ofmetformin and a GK activator may be carries out, in whole or in part, byadministering a metformin salt of a GK activator.

V. EXAMPLES Example 1 Treatment of Diabetic ob/ob Mice with UD1 andMetformin

Before treatment, the mice were assigned to four groups based onbaseline glucose levels and body weight (n=10 for each group). Eachgroup of mice was dosed with one of the following: (1) a controlsubstance; (2) 75 mg/kg UD1; (3) 100 mg/kg metformin (Met); or (4) 75mg/kg UD1 and 100 mg/kg metformin (Met). Post-prandial glucose wasmeasured at time points of 1, 3, 5, 7, and 9 hours following dosing.Table 1 shows the mean glucose levels (in mg/dL) for each group at therecited time points. (The standard deviations for the 10 measurementswere generally les than 10-15% the mean measured BG level.) The last rowof Table 1 shows the change in glucose levels (in terms of glucoselowering) for each group (relative to control) over the course of the 9hours, measured as AUC for 0-9 hours (in hours—mg/dL).

TABLE 1 Time Control UD1 Met Met + UD1 (hours) (mg/dL) (mg/dL) (mg/dL)(mg/dL) 0 388 391 389 393 1 433 321 357 213 3 366 254 334 115 5 461 376459 171 7 447 382 501 222 9 452 394 484 285 AUC 0-9 hrs Control UD1 MetMet + UD1 (h-mg/dL) (h-mg/dL) (h-mg/dL) (h-mg/dL) 0 −748 −39 −2027

As is evident from the AUC for 0-9 hours, the combination therapy of theGK activator (UD1) with a sub-optimal amount of metformin led to aglucose-lowering effect that is in excess of a simply additiveglucose-lowering effect. Thus, the results show a synergistic benefit inob/ob mice in terms of glucose lowering for the combination of UD1 and asub-optimal amount of metformin.

Example 2 Preparation of a Metformin Salt of UD1

NaOH (0.8 g) was dissolved in water (20 mL) and then cooled to roomtemperature. 1,1-dimethylbiguanide hydrochloride (3.6 g) was then addedand stirred to obtain a clear solution. The resulting solution was addedto a suspension of{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid (UD1) (9.1 g) in ethanol (80 mL) with stirring at room temperature.The reaction mixture turned clear in 3-5 minutes. The volatiles wereevaporated to obtain a syrup, which was dissolved in ethanol (100 mL)and then concentrated. White precipitate was obtained when about 50 mLof volatiles were removed by evaporation. This precipitate was filteredand dried under reduced pressure to obtain a 1,1-dimethylbiguanide saltof{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid. The ¹H NMR spectrum recorded in DMSO-d₆ indicated the precipitatecontained{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid and 1,1-dimethylbiguanide in 1:1 ratio.

¹H NMR (400 MHz, DMSO-d₆): δ 0.85 (t, 3H), 1.05-2.15 (m, 20H), 2.92 (s,6H), 3.18 (m, 1H), 3.30 (s, 2H), 3.34 (t, 2H), 3.45 (br, 1H), 7.1 (br,NH protons), 7.21 (s, 1H) ppm.

Example 3 PXRD of a Metformin Salt of UD1

FIG. 1 shows the PXRD diffractogram for a sample containing acrystalline 1:1 salt of metformin and UD1-FA. The data were collectedusing a PANalytical X'Pert Prop diffractometer using Cu-Kα incidentradiation using an Optix long, fine-focus source. Data were collectedand analyzed using X'Pert Pro Data Collector software (v. 2.2b). Priorto analysis, calibration was carried out using the Si 111 peak position.The physical specimen was sandwiched between 3-μm-thick films, analyzedin transmission geometry, and rotated to optimize orientationstatistics. A beam-stop was used. The diffraction pattern was collectedusing a scanning position-sensitive detector (X'Celerator) located 240mm from the specimen.

Example 4A

A metformin salt of UD1-FA was prepared, as described above, andsuspended in water. For comparison, two solid formulations of UD1 wereprepared: a capsule (Example 4B) and a tablet (Example 4C).

Example 4B

57.6 g of TWEEN 80 and 14.4 g of HPMC E3 LV were dissolved in 1100 mL ofwater. 1600.0 g of UD1-FA, 280.0 g of AVICEL PH101, 299.2 g of lactosemonohydrate, and 184.0 g of AC-DI-SOL were transferred to a high sheargranulator. The powder was blended for 2 minutes at 250 rpm with thechopper off. The HPMC/TWEEN 80 solution was then pumped into thegranulator while mixing for 1-2 minutes with an impeller speed of 250rpm and chopper speed of 1000 rpm. Additional water was added tocomplete the granulation. The wet granules were transferred to a VectorFL-Multi-3 Fluid bed drier and dried the granules to LOD of <3.0% usinginlet temperature of 50-60° C. The dried granules were passed through a#30 mesh screen. 2189.4 g of the wet granulation were thoroughly blendedwith 128.02 g of AVICEL PH101, 129.46 g of AC-DI-SOL, 129.46 g ofpregelatinized starch (Starch 1500), and 12.95 g of magnesium stearate.The resulting mixture was then filled in Swedish orange opaque capsulesusing encapsulator equipment. Each capsule weighed 360 mg and contained200 mg of UD1-FA.

Example 4C

12.14 g of UD1-FA, 1.08 g of TWEEN 80, and 0.08 g of HPMCAS weredissolved in 485 mL of THF. The solution was spray dried onto a mixtureof 7.20 g of AVICEL PH101, 7.20 g of lactose DT, and 3.0 g ofcrospovidone using fluidized bed granulation (Vector Laboratory MicroFluid Bed) equipment. The granules were passed through a #60 mesh screento obtain a mixture of fine powder and small granules. 2.55 g of thispowder was thoroughly blended with 0.23 g of AVICEL PH101, 0.16 g ofcrospovidone, 0.38 g of corn starch, 0.05 g of CAB-O-SIL, 0.14 g ofsodium lauryl sulfate, 1.50 g of anhydrous sodium carbonate, 0.50 g ofanhydrous sodium bicarbonate, and 0.03 g of magnesium stearate. Theresulting mixture was compressed into tablets using SC-2 single stationtablet press from Key International; each tablet had hardness of 8-12Kp. Each tablet weighed 555 mg and contained 100 mg of UD1-FA.

Example 4D

The three dosage forms (the salt in water, the capsule, and the tablet)were each administered to three male beagle dogs. For all nine dogs, 100mg of UD1 was administered orally. Each dog was dosed in a fasted state,where food was provided 4 hours following dosing. Blood samples weretaken for pharmacokinetic (PK) evaluation at the following timeintervals following dosing: 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, 12.0, and 24.0hours. Table 2, below, shows the mean results for various PK parametersfor the three groups of dogs.

TABLE 2 Metformin Salt Capsule Tablet Dose (mg/kg) 9.3 10.4 9.8 C_(max)(ng/mL) 6985 4127 6500 t_(1/2) (hours) 2.85 3.01 2.41 AUG_(0-∞) (h ·ng/mL) 15802 11843 14820

The metformin salt of UD1 showed improved PK parameters over the capsuleand even over the tablet that had included carbonate and bicarbonate.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, one of skill in the art will appreciate that certainchanges and modifications may be practiced within the scope of theappended claims. In addition, each reference provided herein isincorporated by reference in its entirety to the same extent as if eachreference was individually incorporated by reference. Where a conflictexists between the instant application and a reference provided herein,the instant application shall dominate.

1-9. (canceled)
 10. A method of improving insulin sensitivity in asubject comprising: administering to the subject a glucokinase activatorin combination with a suboptimal amount of metformin.
 11. The method ofclaim 10, wherein the glucokinase activator is a liver-selectiveglucokinase activator.
 12. The method of claim 10 or 11, wherein theglucokinase activator is{2-[3-cyclohexyl-3-(trans-4-propoxy-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-aceticacid or a pharmaceutically acceptable salt thereof. 13-21. (canceled)